In situ Fe K-edge X-ray absorption spectroscopy study during cycling of Li2FeSiO4 and Li2.2Fe0.9SiO4 Li ion battery materials
MetadataShow full item record
In situ X-ray Absorption Spectroscopy (XAS) results are presented for Li2FeSiO4 and Li2.2Fe0.9SiO4, promising cathode materials for lithium-ion batteries. The aims are to establish the valence and local structure of Fe during charge and discharge to understand if the Fe3+/Fe4+ redox pair can be reached in the current battery design. It is found that the valence state changes between Fe2+ and Fe3+, with no evidence of Fe4+ before the onset of electrolyte degradation. There is a reversible contraction and extension of the Fe–O bond lengths during cycling while the Fe–Si distance remains constant, which underlines the stability of the Li2FeSiO4 material. The same observations apply to Li2.2Fe0.9SiO4 cathode material indicating that changing the stoichiometry does not provide any additional structural stability
Brownrigg , A W , Mountjoy , G , Chadwick , A V , Alfredsson , M , Bras , W , Billaud , J , Armstrong , A R , Bruce , P G , Dominko , R & Kelder , E M 2015 , ' In situ Fe K-edge X-ray absorption spectroscopy study during cycling of Li 2 FeSiO 4 and Li 2.2 Fe 0.9 SiO 4 Li ion battery materials ' Journal of Materials Chemistry A , vol 3 , no. 14 , pp. 7314-7322 . DOI: 10.1039/c4ta06305h
Journal of Materials Chemistry A
Copyright 2015 the Authors. This work is made available online in accordance with the publisher’s policies. This is the author created, accepted version manuscript following peer review and may differ slightly from the final published version. The final published version of this work is available at: https://dx.doi.org/10.1039/C4TA06305H
Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.